The present invention relates to a color television system in which at least one part of the chromatic information is transmitted by suppressed carrier amplitude modulation of a subcarrier and it is therefore necessary to have a periodic reference signal, formed by a subcarrier burst.
Normally such reference signal is inserted every line, on the cancellation pedestal (back porch) which follows the synchronizing signal; this refers for example to the NTSC system which is used, inter alia, in the United States of America and in Japan. The norms for the NTSC system are given for example in "Federal Communications Commission, Public Notices" of Dec. 17, 1953 and June 6, 1954.